1. Field of the Invention
The present invention is broadly concerned with passenger oxygen mask assemblies including relatively low cost, conventional passenger oxygen masks wherein the assemblies are designed to be supported on existing mask-supporting fixtures in commercial aircraft passenger service units. More particularly, the invention is concerned with such mask assemblies, as well as the hangers forming a part thereof, where the hangers are designed for manual attachment to the existing mask fixtures without requiring any fixture modification, and where the standard oxygen masks are releasably supported by the hangers.
2. Description of the Prior Art
All commercial passenger aircraft provide emergency oxygen masks for use by passengers in the event of a cabin depressurization or other emergency. Conventionally, a passenger service unit is located above the passenger seats and has a drop-down door which opens when passenger oxygen is required. In many such service units, the masks drop under the influence of gravity to a location adjacent the passengers. In other designs, the masks are retained on the inner surface of the drop-down door, but can readily be grasped and removed by the passengers.
In one specific design used in DC-9 aircraft, the passenger service unit door has a series of fixtures each designed to support an oxygen mask. However, owing to the configuration of the fixtures, oxygen masks must be provided which are different from most standard masks. That is, the widely used standard passenger oxygen masks cannot be used in the DC-9 aircraft, because such masks do not properly fit onto the preexisting mask fixtures. This presents a real problem, however, inasmuch as the DC-9 masks are considerably more expensive to manufacture than the standard, more widely used masks. In addition, airlines having a mixed fleet of aircraft must purchase and stock the DC-9 masks as well as other masks.
While it would be theoretically possible to redesign the DC-9 passenger service units, this would entail retrofitting of all of the units for all of the DC-9 aircraft. This would represent a very considerable expense to the airlines.
It would therefore be a decided advantage if the standard passenger oxygen masks could be used in DC-9 aircraft without modification or other retrofitting of the passenger service units thereof.
The present invention overcomes the problems outlined above and provides a passenger oxygen mask assembly adapted to be supported on a preexisting mask-supporting fixture. Broadly speaking, the mask assemblies of the invention include a hanger adapted for mounting on the existing fixtures, together with standard oxygen masks supported by the hangers and being manually separable therefrom.
The preferred hangers each include an attachment portion and an adjacent mask-retaining portion. The attachment portion is configured to engage the existing fixture and mount the hanger thereon. The mask-retaining portion on the other hand is designed to support a conventional oxygen mask. The hangers of the invention may be formed from any suitable material such as resilient synthetic resin or wire. The cost of the fixtures is such that owners of DC-9 aircraft experience reduced costs by purchasing and using the hangers with standard masks, as opposed to continuous use of the much more costly DC-9 masks.
In preferred forms, the attachment portions of the hangers include an elongated, shape-retaining central leg having spaced apart ends and a recess intermediate the ends; the recess is configured to receive the upstanding post forming a part of the existing DC-9 mask fixture. The mask-retaining portion is supported by the ends of the attachment portion leg and includes one or more elongated members which at least partially define an opening for receiving the conventional mask.